Average fast neutron flux in three energy ranges in the Quinta assembly irradiated by two types of beams

This work was performed within the international project “Energy plus Transmutation of Radioactive Wastes” (E&T - RAW) for investigations of energy production and transmutation of radioactive waste of the nuclear power industry. 89Y (Yttrium 89) samples were located in the Quinta assembly in order to measure an average high neutron flux density in three different energy ranges using deuteron and proton beams from Dubna accelerators. Our analysis showed that the neutron density flux for the neutron energy range 20.8 - 32.7 MeV is higher than for the neutron energy range 11.5 - 20.8 MeV both for protons with an energy of 0.66 GeV and deuterons with an energy of 2 GeV, while for deuteron beams of 4 and 6 GeV we did not observe this

Average fast neutron flux in three energy ranges in the Quinta assembly irradiated by two types of beams

This work was performed within the international project “Energy plus Transmutation of Radioactive Wastes” (E&T - RAW) for investigations of energy production and transmutation of radioactive waste of the nuclear power industry. 89Y (Yttrium 89) samples were located in the Quinta assembly in order to measure an average high neutron flux density in three different energy ranges using deuteron and proton beams from Dubna accelerators. Our analysis showed that the neutron density flux for the neutron energy range 20.8 - 32.7 MeV is higher than for the neutron energy range 11.5 - 20.8 MeV both for protons with an energy of 0.66 GeV and deuterons with an energy of 2 GeV, while for deuteron beams of 4 and 6 GeV we did not observe this

Comparison of neutron induced fission and capture in Np-237 and Pu-239 irradiated in QUINTA assembly with 660 MeV proton beam

Two Np-237 samples and one Pu-239 were irradiated in spallation neutrons produced in ADS setup QUINTA. The accelerated beam consisted of protons of energy 660 MeV. The method was based on gamma-ray spectrometry measurement. During analysis of the spectra several fission products and one actinide were identified. Fission product activities gave the number of fissions. The actinide (Np-238), a result of neutron capture by Np-237 gave the number of captures. In a similar manner the number of fissions in Pu-239 was determined. The Pu-240, a product of neutron capture by Pu-239, activity was impossible to measure

Comparison of neutron induced fission and capture in Np-237 and Pu-239 irradiated in QUINTA assembly with 660 MeV proton beam

Two Np-237 samples and one Pu-239 were irradiated in spallation neutrons produced in ADS setup QUINTA. The accelerated beam consisted of protons of energy 660 MeV. The method was based on gamma-ray spectrometry measurement. During analysis of the spectra several fission products and one actinide were identified. Fission product activities gave the number of fissions. The actinide (Np-238), a result of neutron capture by Np-237 gave the number of captures. In a similar manner the number of fissions in Pu-239 was determined. The Pu-240, a product of neutron capture by Pu-239, activity was impossible to measure

Comparison of two fast neutron fluence measurement methods based on Np-237 fission-to-capture ratio measurement (spectral index) and a reverse dark current measurement in a planar silicon detector

The idea of the first method is to search the neutron energy for the ratio of fission cross section to capture cross section of the selected actinide isotope from the nuclear data base that is equal to the measured ratio of the fissioned and captured actinide isotope Np-237. The idea of the second method consists in the measurement of the reverse dark current increase, which is linearly proportional to neutron fluence, induced by the fast neutron irradiation in planar silicon detectors. Np-237 samples and planar silicon detectors were placed inside a subcritical assembly (the Quinta assembly at the Joint Institute for Nuclear Research, Russia) very close to each other assuming that in both samples the same neutron fluence should pass. We concluded that minor actinide samples and planar silicon detectors can be used as neutron fluence detectors especially in the high neutron energy range, where measurements are difficult. Considering the importance of high energy neutron measurement in the ADS (Accelerator Driven System), actinide and silicon detectors could be a very useful tool

Comparison of two fast neutron fluence measurement methods based on Np-237 fission-to-capture ratio measurement (spectral index) and a reverse dark current measurement in a planar silicon detector

The idea of the first method is to search the neutron energy for the ratio of fission cross section to capture cross section of the selected actinide isotope from the nuclear data base that is equal to the measured ratio of the fissioned and captured actinide isotope Np-237. The idea of the second method consists in the measurement of the reverse dark current increase, which is linearly proportional to neutron fluence, induced by the fast neutron irradiation in planar silicon detectors. Np-237 samples and planar silicon detectors were placed inside a subcritical assembly (the Quinta assembly at the Joint Institute for Nuclear Research, Russia) very close to each other assuming that in both samples the same neutron fluence should pass. We concluded that minor actinide samples and planar silicon detectors can be used as neutron fluence detectors especially in the high neutron energy range, where measurements are difficult. Considering the importance of high energy neutron measurement in the ADS (Accelerator Driven System), actinide and silicon detectors could be a very useful tool